The present invention relates generally to a motorized operator for an upwardly acting door. More particularly, the present invention relates to a method of installing such an operator to reduce parasitic drag or binding produced by misalignment between the operator, counter balance system, and mounting bracket. More specifically, the present invention relates to a method of automatically relatively aligning the operator, the mounting bracket, the counterbalance system, and the door opening frame.
In a motorized door operator system, an operator assembly is used to power a door from a closed position to an open position and vice versa. In one type of operator system, the motor has drive components that are coupled to driven components in a counterbalance system. When the drive components are misaligned relative to driven components, these components may bind or even lock up making it difficult to properly operate the door. In less serious instances, misalignment produces parasitic drag that saps operator power and imparts excessive wear to the operator components. To cope with this problem, manufacturers have provided an allowance for some misalignment in their door systems. Often the operator is connected to the counterbalance system by way of a flexible element, such as an endless belt or chain. Likewise, operator assemblies that are attached to a track system use flexible couplers to prevent parasitic loading or binding. The flexibility of these various couplers permits some misalignment between the drive components of the operator motor and the driven components of the counterbalance system. In other words, since the coupling between the operator and counterbalance assemblies is flexible a binding condition will not occur.
In one door operator system known in the industry, the operator is placed directly above the counterbalance system and mounted to the header. A drive shaft from the operator extends outside of the housing and carries a sprocket. A second sprocket is carried on the counterbalance shaft, and the two sprockets are coupled by a chain. In this way, if the operator is laterally misaligned or misaligned in a plane extending perpendicular to the door frame, the flexibility of the chain will allow for this misalignment and maintain a proper driving relationship between these components. If the lateral misalignment is severe, either sprocket may be slid along its respective shaft to regain proper alignment without having to move the operator. The use of the chain requires the operator be mounted some distance from the counterbalance system increasing the space necessary to mount the operator system. Further, the use of a flexible element, such as a chain, makes installation somewhat more involved. The installer must properly space the operator from the counterbalance system to ensure proper tensioning of the chain. Further, as previously mentioned, the sprockets on the operator shaft and counterbalance drive shaft must be aligned sufficiently that the operator may drive the counterbalance drive shaft without having the chain slip off of one of the sprockets.
Other door operating systems in the industry that directly drive the counterbalance drive shaft have the advantage of eliminating the space needed to tension the chain. One such system receives the counterbalance shaft within the operator housing and employs an operator having a worm gear that meshes with a gear on the counterbalance shaft to effect rotation thereof. In this system, the operator is placed immediately adjacent to the counterbalance system. While decreasing the space taken up by the operator system, this system gives up the simplicity of aligning the drive components to the driven components found in a flexible drive member system. Since there is direct interaction between the gears found on the operator assembly and the counterbalance assembly, there is little or no flexibility within the meshing of the gears to allow for parasitic drag or binding. Also, the drive tube is confined by the operator housing and, thus, cannot move to accommodate any significant extent of misalignment. Slight misalignment that could provoke binding or place a drag on the system may not be readily visible to the installer. Ordinarily, the installer is able to detect significant vertical misalignment of the operator or drive shaft with respect to each other. Since the cable drums, mounting hardware and other components make it difficult to view the system from its ends, misalignment in the plane perpendicular to the header is difficult to detect. Therefore, a misaligned operator may not be discovered until the door is operated, if at all. Consequently, based on the desirability of using such compact direct drive systems, there is a need for a simple method of aligning an operator assembly in such systems.
In light of the foregoing, an object of the present invention is providing a simple method of aligning a direct drive operator in a door operating system. A further object of the present invention is to provide such a method that automatically aligns an operator, an operator mounting bracket, and a counterbalance system in a door operating system. Still a further object of the present invention is to provide a method of aligning a direct drive operator in a door operating system where the door is manually cycled while the operator is loosely attached to align the operator and counterbalance system. Yet another object of the present invention is to provide such a method where the drive is disconnected before manually cycling the door. Still a further object of the present invention is to provide such a method where the door is moved from a closed position to an open position and returned to the closed position.
In view of at least one of these objects, the present invention generally provides a method of aligning an operator in a system for operating an upwardly acting door including providing an operator that directly interrelates with a counterbalance assembly in the door operating system to move the door, where the operator is at least partially supported on the counterbalance system, loosely attaching the operator to a header adjacent the door, and moving the door from a closed position to an open position and returning the door to the closed position to achieve alignment.
The present invention still further provides a method of aligning an operator in a door operating system for operating an upwardly acting door, where the operator fits on or around the drive tube of a counterbalance system including mounting the operator on a header adjacent the door; loosely attaching the operator to the header by fasteners, vertically moving the door, and subsequently tightening the fasteners to firmly attach the operator to said header.
The present invention further provides a method of aligning an operator and a counterbalance system relative to a fixed header including, mounting the counterbalance system on the header in operative relation to the door, positioning the operator in direct working interrelationship with the counterbalance system, loosely attaching the operator to the header by a mounting bracket, cycling the door from a closed position to an open position and returning the door to the closed position to permit self-alignment between the counterbalance system, operator and the header, and securely attaching the operator to the header after cycling the door.